A communication system can be seen as a facility that enables communication sessions between two or more entities such as mobile communication devices and/or other stations associated with the communication system. A communication system and a compatible communication device typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. For example, the manner how the communication device can access the communication system and how communications shall be implemented between communicating devices, the elements of the communication network and/or other communication devices is typically defined.
In a wireless communication system at least a part of communications between at least two stations occurs over a wireless link. Examples of wireless systems include public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). In wireless systems a network element or network entity (NE) or access node is provided by a base station. The radio coverage area of a base station is known as a cell, and therefore the wireless systems are often referred to as cellular systems. In some systems, for example a 3GPP standard system, a base station access node is called Node B (NB) or an enhanced Node B (eNB).
A user can access the communication system by means of an appropriate communication device. A communication device of a user is often referred to as user equipment (UE). A communication device is provided with an appropriate signal receiving and transmitting arrangement for enabling communications with other parties. A communication device may be arranged to communicate, for example, data for carrying communications such as voice, electronic mail (email), text message, multimedia, for enabling internet access and so on. Users may thus be offered and provided numerous services via their communication devices. The communication connection can be provided by means of one or more data bearers.
In wireless systems a communication device provides a transceiver station that can communicate with the access node and/or another communications device. A communication device or user equipment may also be considered as being a part of a communication system. In certain applications, for example in ad-hoc networks, the communication system can be based on use of a plurality of user equipment capable of communicating with each other.
Network management is a complex task. Complexity arises on the one side from the number of network elements (NEs) that have to be deployed and managed, and on the other side from interdependencies between the configuration and the status of the deployed network elements in terms of performance, faults, etc. In a heterogeneous network the variety of deployed technologies and their proprietary operational paradigms are difficult to handle. The configuration, optimization and troubleshooting of the management of the network therefore requires high expertise and operational management workflows to be typically performed by human operators supported by software tools. However, such manual and semi-automated management is time-consuming, error-prone, and potentially unable to react quickly enough to network changes and thus expensive.
It has been a goal of network management designers to attempt to automate operation, administration and management (OAM) functions by the deployment of “Self Organizing Networks” (SON). While SON concepts are generically applicable, these focus of developments has been to Radio Access Networks (RAN) due to the large number of NE (base stations) distributed over large geographical areas (and thus the incurred cost to doing remote and on-site management activities). In particular, for the long term evolution (LTE) and long term evolution-advanced (LTE-A) radio access network (RAN) standards such as evolved universal mobile telecommunications system (UMTS) Terrestrial Radio Access Network (E-UTRAN), SON is considered a useful building block, due to the potential high degree of distribution and heterogeneity. In such networks there may be a wide range of telecommunications standards being employed such as concurrent operation of 2G/3G/LTE/LTE-A network elements. Furthermore LTE networks may be heterogeneous in structure, for example employing LTE multi-layer structures where there can be pico cells, micro cells, and macro cells all operating over the same geographical range.
According to an aspect, there is provided a method comprising: receiving from a plurality of user equipment signal information for at least one cell; and using said information to determine if a candidate cell is to enter a reduced power mode.
The signal information may be handover information.
The signal information may comprise at least one of signal strength information and signal quality information.
The signal information may comprise at least one of reference signal receive power and reference signal receive quality.
The method may comprise receiving from each of said plurality of user equipment, signal information for a serving cell and at least one other cell, different to said candidate cell.
The method may comprise receiving information for each cell neighbouring said candidate cell for which a determination is to be made as to whether said candidate cell is to enter a reduced power mode.
The method may comprise using said received information to determine a probability of an outage for a user equipment if said candidate cell is entered into a reduced power mode.
The determining a probability of an outage may be dependent on information for one or more user equipment which only receive signals from a serving cell.
The candidate cell may be entered into a reduced power mode if said probability of an outage is less than a threshold.
The reduced power mode may comprise switching said cell off.
The method may comprise if it is determined that a candidate cell is not to enter a reduced power mode, causing at least one parameter of at least one neighbouring cell to be altered and repeating said method.
The at least one parameter may comprise at least one of antenna configuration; antenna orientation; transmission power; and uplink power control parameters.
The method may be performed in a base station, a controller, element manager or network management system.
A computer program comprising program code means adapted to perform the method may also be provided. The computer program may be stored and/or otherwise embodied by means of a carrier medium.
According to another aspect, there is provided an apparatus comprising: means for receiving from a plurality of user equipment signal information for at least one cell; means for using said information to determine if a candidate cell is to enter a reduced power mode.
The signal information may be handover information.
The signal information may comprise at least one of signal strength information and signal quality information.
The signal information may comprise at least one of reference signal receive power and reference signal receive quality.
The using means may be for comparing said signal information for at least one cell with a minimum value for said signal information.
The using means may be for comparing said signal information for at least one cell with a minimum value for said signal information.
The receiving means may receive from each of said plurality of user equipment, signal information for a serving cell and at least one other cell, different to said candidate cell.
The receiving means may receive information for each cell neighbouring said candidate cell for which a determination is to be made as to whether said candidate cell is to enter a reduced power mode.
The using means may be for using said received information to determine a probability of an outage for a user equipment if said candidate cell is entered into a reduced power mode.
The using means may be for determining a probability of an outage dependent on information from one or more user equipment which only receive signals from a serving cell.
The using means may be for entering said candidate cell into a reduced power mode if said probability of an outage is less than a threshold.
The reduced power mode may comprise switching said cell off.
The using means may if it is determined that a candidate cell is not to enter a reduced power mode, cause at least one parameter of at least one neighbouring cell to be altered and repeating said method.
The at least one parameter may comprise at least one of antenna configuration; antenna orientation; transmission power; and uplink power control parameters.
According to another aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer code for one or more programs, the at least one memory and the computer code configured, with the at least one processor, to cause the apparatus at least to: receive from a plurality of user equipment signal information for at least one cell; and use said information to determine if a candidate cell is to enter a reduced power mode.
The signal information may be handover information.
The signal information may comprise at least one of signal strength information and signal quality information.
The signal information may comprise at least one of reference signal receive power and reference signal receive quality.
The at least one memory and the computer code may be configured, with the at least one processor, to cause the apparatus to receive from each of said plurality of user equipment, signal information for a serving cell and at least one other cell, different to the candidate cell.
The at least one memory and the computer code may be configured, with the at least one processor, to cause the apparatus to receive information for each cell neighbouring said candidate cell for which a determination is to be made as to whether said candidate cell is to enter a reduced power mode.
The at least one memory and the computer code may be configured, with the at least one processor, to cause the apparatus to use said received information to determine a probability of an outage for a user equipment if said candidate cell is entered into a reduced power mode.
The at least one memory and the computer code may be configured, with the at least one processor, to cause the apparatus to determining a probability of an outage by determining one or more user equipment which only receive signals from a serving cell.
The at least one memory and the computer code may be configured, with the at least one processor, to cause the apparatus to cause said candidate cell to be entered into a reduced power mode depending on a probability of an outage. In some embodiments the candidate cell may be entered into a reduced power mode if a probability of an outage is less than a threshold.
The reduced power mode may comprise switching said cell off.
If it is determined that a candidate cell is not to enter a reduced power mode, the at least one memory and the computer code may be configured, with the at least one processor, to cause at least one parameter of at least one neighbouring cell to be altered and repeating the analysis or method.
The at least one parameter may comprise at least one of antenna configuration; antenna orientation; transmission power; and uplink power control parameters.
A base station, controller, element manager or network management system may comprise the apparatus.
Various other aspects and further embodiments are also described in the following detailed description and in the attached claims.